Georgeson M A
Perception. 1976;5(1):99-111. doi: 10.1068/p050099.
After inspection of vertical sinusoidal gratings at least three distinct types of subjective or "hallucinated" patterns can be seen on a uniform test field. One type, here called horizontal streaming (H), is already well-known from the work of MacKay. A second type (V) looks like aroughly sinusoidal grating about 1-5 octaves above the adapting spitial frequency. Under optimal conditions a second vertical component appears at about 2 octaves below the adapting frequency. The third category of aftereffect consists of diagonal lines (D) at two orientations (about +/-40 degrees from vertical). The spatial-frequency band at these two orientations appears to be fairly broad, but roughly similar to the adapting frequency. The duration and strength of D increased, while V declined, at higher adapting spatial frequencies. D and V were increasing functions of adapting contrast, while H appeared abruptly only after the highest adapting contrast. H, D, and V are thus all functionally distinct. A schematic model of cortical organization is proposed to account for these phenomena. Pattern channels selective for a given orientation are grouped together with movement channels selective for the orthogonal direction. Antagonism between channels within such "modules" accounts for the streaming effect (H). Inhibition between modules tuned to different orientations and spatial frequencies accounts for the D and V effects: after adaptation of channels in one module, neighbouring module(s) are released from inhibition to produce a spurious response which is seen as a grating-like object in the adapted part of the visual field. During flickering adaptation a "halluncinated" lattice can be seen superimposed on the adapting grating. It apparently consists of Fourier components more remote from the adapting pattern than D and V are. This disinhibitory effect is strong confirmation of the inhibitory model. The regular and highly organized matrix of channels implied by these experiments may constitute a cortical hypercolumn conducting a coarse, piecewise Fourier transformation of the retinal image.
在对垂直正弦光栅进行检查后，在均匀的测试视野上可以看到至少三种不同类型的主观或“幻觉”图案。一种类型，这里称为水平流（H），已经从麦凯的研究中广为人知。第二种类型（V）看起来像是在适应空间频率之上约1 - 5个八度的大致正弦光栅。在最佳条件下，第二个垂直分量出现在适应频率以下约2个八度处。后效的第三类由两个方向（与垂直方向约成+/-40度）的对角线（D）组成。这两个方向上的空间频率带似乎相当宽，但大致与适应频率相似。在较高的适应空间频率下，D的持续时间和强度增加，而V则下降。D和V是适应对比度的递增函数，而H仅在最高适应对比度之后才突然出现。因此，H、D和V在功能上都是不同的。提出了一个皮质组织的示意图模型来解释这些现象。对给定方向有选择性的图案通道与对正交方向有选择性的运动通道组合在一起。这种“模块”内通道之间的拮抗作用解释了流效应（H）。调谐到不同方向和空间频率的模块之间的抑制作用解释了D和V效应：在一个模块中的通道适应后，相邻模块从抑制中释放出来，产生一个虚假响应，在视野的适应部分被视为一个类似光栅的物体。在闪烁适应期间，可以看到一个“幻觉”晶格叠加在适应光栅上。它显然由比D和V更远离适应图案的傅里叶分量组成。这种去抑制效应有力地证实了抑制模型。这些实验所暗示的规则且高度有组织的通道矩阵可能构成一个对视网膜图像进行粗略的、分段傅里叶变换的皮质超柱。
